Antibacterial activity of Dioscorea bulbifera Linn. extract and its active component flavanthrinin against skin-associated bacteria oleh Donruedee Sanguansermsri, Phanchana Sanguansermsri, Kittisak Buaban, Vachira Choommongkol, Chareeporn Akekawatchai, Noree Charoensri, Ian Fraser, Nalin Wongkattiya